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Validação de um método para análise de polióis em alimentos por cromatografia líquida de ultra eficiência
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 1.93 MB | Adobe PDF |
Advisor(s)
Abstract(s)
Os polióis são carboidratos provenientes da hidrogenação da sua fonte de açúcar,
em que o grupo carbonilo do aldeído ou da cetona é reduzido a um grupo hidroxilo
primário ou secundário. Na indústria alimentar, os polióis têm vindo a ser cada vez mais
utilizados como substitutos da sacarose, em consequência da maior procura por um
estilo de vida mais saudável ou devido a doenças como a diabetes ou obesidade.
Neste âmbito, a empresa SGS quis validar um método que permitisse quantificar,
com elevada confiança, polióis presentes nas formulações de diversos alimentos,
através da técnica de cromatografia líquida de ultra eficiência com deteção por índice
de refração. A validação engloba os polióis xilitol, sorbitol e maltitol.
Inicialmente, o método começou por demonstrar ser específico e seletivo, uma
vez que ao injetar soluções individuais e conjuntas de polióis, e variando a
concentração, não se verifica influência no seu tempo de retenção. Para cada um dos
polióis referidos, o método foi considerado linear e mostrou ser mais sensível para a
quantificação de maltitol e sorbitol do que para xilitol. O limite de quantificação diz
respeito ao padrão de menor concentração, isto é, 0,05%. Verificou-se que a gama de
trabalho de 0,05% a 3% era adequada pois através do teste de homogeneidade de
variâncias confirmou-se que as variâncias nos limites da gama de trabalho não são
significativamente diferentes. Para a repetibilidade realizaram-se 10 réplicas do padrão
de 0,05% e de 3% para cada analito, bem como de amostra. Analisaram-se de seguida
os coeficientes de variação da repetibilidade, que se verificaram estar abaixo do limite
estabelecido de 10%. Para a precisão intermédia foram realizadas 3 réplicas do padrão
de 0,05% e de 3%, assim como de amostra, em 3 dias diferentes. O objetivo era verificar
qual a influência do fator dia nos resultados obtidos. Dados os baixos coeficientes de
variação registados, o método mostrou ser preciso, comprovando assim que o fator dia
não teve influência nos resultados obtidos. A exatidão foi avaliada com base em ensaios
de recuperação, sendo que as taxas de recuperação deveriam estar compreendidas no
intervalo de 80 % a 120 % para a exatidão ser considerada satisfatória. Como todas as
taxas de recuperação obtidas estavam dentro deste intervalo, pôde afirmar-se que o
método possui uma boa exatidão.
Dado que todos os parâmetros testados apresentaram resultados satisfatórios, a
validação do método foi bem-sucedida.
Polyols are carbohydrates resulting from the hydrogenation of their sugar source, in which the carbonyl group of the aldehyde or ketone is reduced to a primary or secondary hydroxyl group. In the food industry, polyols have been increasingly used as sucrose substitutes, as a result of the greater demand for a healthier lifestyle or due to diseases such as diabetes or obesity. In this context, the company SGS wanted to validate a method that would make it possible to quantify, with high confidence, the polyols present in the formulations of various foods, through the technique of ultra-performance liquid chromatography with refractive index detection. The validation encompasses xylitol, sorbitol and maltitol polyols. Initially, the method began by demonstrating to be specific and selective, since when injecting individual and joint solutions of polyols and varying the concentration, there is no influence on their retention time. For each of the mentioned polyols, the method was considered linear and proved to be more sensitive for the quantification of maltitol and sorbitol than for xylitol. The limit of quantification refers to the lowest concentration standard, ie 0.05%. It was found that the working range of 0.05% to 3% was adequate because through the variance homogeneity test was confirmed that the variances at the limits of the working range are not significantly different. For repeatability, 10 replicates of the 0.05% and 3% standard were performed for each analyte, as well as the sample. The repeatability coefficients of variation were analyzed below, which were found to be below the established limito of 10%. For intermediate precision, 3 replicates of the 0.05% and 3% standard, as well as the sample, were performed on 3 different days. The objective was to verify the influence of the day factor on the results obtained. Given the low coefficients of variation recorded, the method proved to be precise, thus proving that the day factor had no influence on the results obtained. Accuracy was evaluated based on recovery tests, and recovery rates should be in the range of 80% to 120% for accuracy to be considered satisfactory. As all the recovery rates obtained were within this range, it could be stated that the method has good accuracy. As all parameters tested showed satisfactory results, the validation of the method was successful.
Polyols are carbohydrates resulting from the hydrogenation of their sugar source, in which the carbonyl group of the aldehyde or ketone is reduced to a primary or secondary hydroxyl group. In the food industry, polyols have been increasingly used as sucrose substitutes, as a result of the greater demand for a healthier lifestyle or due to diseases such as diabetes or obesity. In this context, the company SGS wanted to validate a method that would make it possible to quantify, with high confidence, the polyols present in the formulations of various foods, through the technique of ultra-performance liquid chromatography with refractive index detection. The validation encompasses xylitol, sorbitol and maltitol polyols. Initially, the method began by demonstrating to be specific and selective, since when injecting individual and joint solutions of polyols and varying the concentration, there is no influence on their retention time. For each of the mentioned polyols, the method was considered linear and proved to be more sensitive for the quantification of maltitol and sorbitol than for xylitol. The limit of quantification refers to the lowest concentration standard, ie 0.05%. It was found that the working range of 0.05% to 3% was adequate because through the variance homogeneity test was confirmed that the variances at the limits of the working range are not significantly different. For repeatability, 10 replicates of the 0.05% and 3% standard were performed for each analyte, as well as the sample. The repeatability coefficients of variation were analyzed below, which were found to be below the established limito of 10%. For intermediate precision, 3 replicates of the 0.05% and 3% standard, as well as the sample, were performed on 3 different days. The objective was to verify the influence of the day factor on the results obtained. Given the low coefficients of variation recorded, the method proved to be precise, thus proving that the day factor had no influence on the results obtained. Accuracy was evaluated based on recovery tests, and recovery rates should be in the range of 80% to 120% for accuracy to be considered satisfactory. As all the recovery rates obtained were within this range, it could be stated that the method has good accuracy. As all parameters tested showed satisfactory results, the validation of the method was successful.
Description
Keywords
Sacarose Validação Xilitol Sorbitol Maltitol Sucrose Validation Xylitol